Apparatus for rewashing raw wool



March 31, 1970 H. FLEISSNER 3,503,229

APPARATUS FOR REWASHING RAW WOOL Filed Nov. 22, 1966 Inventor:

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0770 EMS Y United States Patent O M 3,503,229 APPARATUS FOR REWASHING RAW WOOL Heinz Fleissner, Egelsbach, near Frankfurt am Main, Germany, assignor to Vepa AG, Basel, Switzerland Filed Nov. 22, 1966, Ser. No. 596,212 Claims priority, application Gegrmany, Nov. 22, 1965,

Int. Cl. D061? 29/00 U.S. Cl. 68-18 9 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION The present invention relates to an apparatus for rewashing raw wool which has been prewashed with a solvent. More specifically, the present invention concerns an apparatus comprising a train of conveying elements which is used to convey the raw wool through the treatment medium.

In washing wool, it is well known to use, instead of water, a solvent which can dissolve the wool fat. The dissolved wool fat can then be recovered from the solvent. Several such wool washing methods using a solvent as the detergent liquor are well known. However, all of these methods contain the inherent disadvantage that when using the solvent in the first line, only the wool fat is re moved from the raw wool whereas the other contaminants contained in the Wool, such as for example, suint matter, sand, vegetable matter, mud, etc., remain in the wool. Furthermore, in prior art methods it has proven to be difficult to remove the solvent completely from the wool. Consequently, several washing steps with water are necessary after the solvent treatment.

A well known solvent used for cleaning wool is trichlorethylene. This solvent offers the advantage that it is non-inflammable and that it boils at 73 C. in the presence of water. Therefore, trichlorethylene can be extracted from the wool, shock-like, in hot water at a temperature which is higher than the afore-mentioned boiling point, for example about 80 to 90 C. at the sudden transition from the liquid to the gaseous phase a vigorous cavitation occurs. The gas bubbles which form in the wool open the fibers and the fiber tufts. Tests have also shown that the wool tips which are coalesced with dirt and mud are opened so that the removal of the solid matter, that is, the contaminates from the wool, is substantially facilitated and sped up. Solvents other than trichlorethylene can also be used provided they have a boiling point lower than the boiling point of water.

However, when using the solvent washing method for treating loose wool, aysubstantial problem was encountered. Because of the vigorous cavitation caused by the evaporation of the solvent, the wool is forced to the waters surface so that a portion of the wood does not sufficiently come into contact with the hot water. Furthermore, only a small amount of the solvent is removed from the wool, and in some cases no solvent is removed. That portion of the wool which extends out of the water is thus insufiiciently opened. For these reasons, the solvent wash method for washing wool is used only rarely, and

Patented Mar. 31, 1970 when used, is generally limited to degreasing wool fabrics of all types.

An object of the present invention is to eliminate the disadvantages of the prior art apparatus for Washing wool.

Another object of the present invention is to provide an apparatus for rewashing raw wool which has been prewashed with solvents, wherein the treatment medium is heated to a temperature which is higher than the volatilization temperature of the solvent contained in the wool.

A further object of the present invention is to provide an apparatus which insures substantial contact of the treatment medium with the raw Wool to be treated.

A still further object of the present invention is to provide an apparatus with means for conveying the raw wool to be treated through the treatment medium to the outlet of the treatment bath.

Still another object of the present invention is to provide an apparatus for complete removal of the solvent as well as a good and complete opening of the raw wool tufts, thus effecting a substantial cleaning of the raw wool.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

SUMMARY OF THE INVENTION According to the present invention an apparatus which effects a uniform and efiicient treatment of wool has been produced which comprises a conveying element disposed in a treatment container, said conveying element being at least partially immersed in a treatment liquid in said container and advantageously slightly declined towards the outlet of the container. The conveying element is a gaspermeable conveyor belt which guides the loose wool at its lower surface. The loose wool is transferred from the lower surface of the conveyor belt to the lower surface of a discharge device, which guides the wool from the treatment apparatus. Thus the conveyor belt and the discharge device insure substantial contact of the wool with the treatment medium which can be for example water. The discharge device of the present invention is a suction drum which is subjected to a suction draft and which functions to convey the washed wool to a pair of squeeze rollers and/or a squeezer located behind the suction drum. For sealing the treatment bath against the pair of squeeze rollers, it is advantageous to provide a short chute between the suction drum and the pair of squeeze rollers, such chute being mounted to the face of the treatment bath. Alternatively, the face of the bath can be designed as a short chute.

In accordance with the present invention, the immersion of the wool, enriched with moisture, in the heated treatment bath is facilitated by locating an impeller or bolt drum and/ or roller at a distance from the conveyor belt such that the surface of the impeller or bolt drum and/or roller, together with the surface of the conveyor belt forms a feeding funnel for the wool. Through the motion of the conveyor belt and the impeller or bolt drum and/or roller, the wool is immersed in the treatment liquid, and by the vigorous cavitation which is initiated, the wool is held to the lower surface of the conveyor belt and is guided by the conveyor belt through the treatment liquid to the discharge suction drum. Advantageously, the conveyor belt can be provided with chain lines which facilitate the immersion of the wool at the inlet.

Effective transportation of the wool in the treatment liquid is further facilitated if at the bath inlet a perforated chute is provided through which the liquid can be drawn in by the suction drum located at the bath outlet. Thus the treatment liquid can be returned to the treatment bath and a flow in the direction of material passage can be constantly maintained in the treatment bath.

The treatment bath or container of the present invention can also be provided with a suction hood containing a fan. The suction hood provides for the collection of the evaporated solvent which can be transferred toa recovery plant through suitable pipes, not shown in the figure.

BRIEF DESCRIPTION OF THE DRAWING The present invention will become fully understood by referring to the acompanying drawing which shows a longitudinal section of one embodiment of the Wooltreating apparatus of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing, the apparatus of the present invention comprises a liquid container 1 which is provided with a perforated intermediate bottom 2 and with a perforated chute 3 at the inlet. Raw wool 5 is fed to the apparatus by means of a conveyor belt 4 and then immersed in a hot'treatment liquid 15 by means of an impeller drum 6 and a conveyor belt 7. The hot treatment medium advantageously is water which is maintained at a temperature higher than the boiling point of the solvent contained in the raw wool, thus efi'ecting evaporation of the solvent from the wool, but not so high as to cause evaporation of the water. Thus, because of the hot treatment liquid, the solvent applied to the wool in the preceding solvent bath and still adhering to the wool is evaporated. The vigorous cavitation which is thus produced forces the wool to the lower surface of the gas-permeable conveyor belt which in turn transports the wool through the bath towards the outlet of the container, and transfers the wool to a suction drum 8 subjected to a suction draft which is provided at the end of the container. The suction draft of the suction drum forms an even wool fleece which is fed through a short chute 9 to a pair of rollers 10. The short chute serves for safely sealing the treatment bath against the pair of rollers. In the suction drum one or several pumps ar arranged, and the liquid drawn in is led laterally out of the suction drum through a pressure channel 12 and is returned to the treatment bath preferably to the perforated chute at the inlet of the bath. It is also possible to return part or all of the treatment liquid into the treatment bath beneath the perforated intermediate bottom. Thus an upward flow is produced in the treatment bath which carries the wool particles which may have deposited on the intermediate bottom upward towards the suction drum. Thus, an automatic cleaning of the treatment bath is achieved. Above the container, a collecting hood 13 is provided for collecting the evaporated treatment liquid and/or solvent. A fan 14 is disposed within the collecting hood and functions to return the gases drawn off to a recovery plant through suitable pipes, not shown. Number 11 in the drawing is a suction pump.

According to the present invention it can be readily seen that the conveyor belt prevents the treatment liquid, and especially the wool floating in the treatment liquid, from boiling up and rolling, and thus felting the wool is substantially eliminated. Therefore, because of proper guidance of the loose wool together with the formation of a fleece on the suction drum and uniform squeezing by the rollers, substantially complete removal of the solvent as well as a good and complete opening of the raw wool tufts can be achieved.

The treatment liquid can be heated to the treatment temperature either by the direct introduction of steam, or by indirect heating means, for example heating coils, which can be installed in the container to heat the treatment liquid to the desired treatment temperature. The treating temperature can be maintained by a regulator which controls the feeding of the heating medium, for example, steam, but it is also possible to regulate the steam supply manually.

Since modifications of this invention will be apparent to those skilled in the art, it is not desired to limit the invention to the exact constitution shown and described. Accordingly, all suitable modifications and equivalents may be resorted to as would be apparent to one skilled in the art.

It is claimed:

1. An apparatus for washing raw wool which comprises a liquid container, an endless belt conveying means disposed within said container, said conveying means being slightly declined toward the outlet of the container and being at least partially immersed in a treatment liquid in said container, an impeller drum disposed in said container at its inlet and next to the end of said conveying means such that the surfaces of said impeller drum and said conveying means form a feeding funnel for the wool, and a suction drum provided at the outlet of said container and next to the end of said conveying means to provide a continuing surface for the wool to the outlet of the liquid container.

2. The apparatus of claim 1 wherein a pair of squeeze rollers are connected behind the suction drum.

3. The apparatus of claim 2, wherein between the suction drum and the pair of squeeze rollers, a short chute is provided for sealing the treatment bath against the pair of squeeze rollers.

4. The apparatus of claim 3 wherein the chute is mounted to the outlet face of the container or the outlet face of the container is designed as a short chute.

5. The apparatus of claim 1 wherein the impeller drum is a pin drum or a roller.

6. The apparatus of claim 1 wherein the conveying means is a gas-permeable conveyor belt which is provided with chain lines.

7. The apparatus of claim 1 wherein a perforated chute is provided at the container inlet, through which chute the liquid drawn in by the suction drum at the end of the container is returned to the container, so that a flow in the direction of material passage is produced in said container.

8. The apparatus of claim 1 wherein a perforated intermediate bottom is disposed within said container which produces an upward flow of the treatment liquid in the container which carries the wool particles which have been deposited on the intermediate bottom towards the suction drum.

9. The apparatus of claim 1 wherein a suction hood is provided above the container and is provided with a fan which transfers the gaseous solvent which has been drawn off to a recovery plant through suitable pipe means.

References Cited UNITED STATES PATENTS 263,728 9/1882 Sargent et a1. 68-158 XR 663,452 12/1900 Maertens 68-158 XR 2,442,012 5/1948 Leonard 68-158 XR 2,736,632 2/1956 Blau 68-18 XR 3,410,119 11/1968 Fleissner 68-158 X R 3,440,843 4/1969 Fleissner 68-158 XR ROBERT L. BLEUTGE, Primary Examiner US. Cl. X.R. 

